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161.
S. N. Bhattacharya 《Rheologica Acta》1981,20(3):288-298
Summary Rheological study of sewage sludge is useful for the design, operation and control of sewage treatment plants. The rheology is highly dependent on physical, chemical and biological characteristics of the sludge. A pipeline rheometer is described in this paper for measurement of rheological properties of the sludge. Primary sewage sludge is a complex flocculated suspension having no fixed particle dimension, shape, size distribution or surface characteristics. The information available so far on rheology of sewage sludge is not suitable for application in design because of the lack of data on physico-chemical characteristics of this sludge.Primary and digested sewage sludge are non-Newtonian in character. Both exhibit yield stress and while primary sludge is shear-thinning in nature, digested sludge has been found to be shear-thickening. Parabolic and yield-power law models have been used to express the experimental data obtained for sludges at various concentrations and temperatures. Yield stress of primary sludge varies exponentially with concentration and linearly with temperature within the short temperature range studied. Primary sludge is found to be antithixotropic at low shear stress. Digested sludge does not exhibit time dependency.With 9 figures and 5 tables 相似文献
162.
Summary The migration velocities of the boundary of As2S3 and Fe(OH)3 sols have been measured under constant current. A new set up for measuring the movement of the boundary under constant current
has been devised. The changes in the boundary movement with time have been observed under constant current condition and it
has been discussed and suggested that measurements of cataphoretic velocity of colloidal particles under constant current
is theoretically more cogent than the measurements taken under constant voltage, because the changes in the resistance shown
by the changes in the potential developed across the different elements in the U-tube at constant current give a more correct
picture of what happens in the cataphoretic tube when cataphorisis takes place. A potentio-valve-voltmeter has been employed
to measure the instantaneous changes of voltage across the mainU-tube without any time lag. This is a new device which has not been tried before.
Zusammenfassung Die Wanderungsgeschwindigkeit an der Grenze von As2S3 and FeOH3-Solen wurde gemessen, und zwar bei konstantem Strom. Eine neue Methode zur Messung der Wanderung bei konstantem Strom wird vorgeschlagen. Die Ver?nderungen der Bewegung der Grenze mit der Zeit werden diskutiert, und es wird vermutet, da? Messungen der kataphoretischen Geschwindigkeit von Kolloidpartikeln bei konstantem Strom theoretisch mehr Aussagen geben als Messungen bei konstanter Spannung, weil Widerstands?nderungen in den einzelnen Teilabschnitten des Kataphoreserohres bei konstantem Strom ein korrekteres Bild gibt. Ein Potentialr?hrenvoltmeter wurde für die Messung des Spannungsabfalls angewendet, so da? zeitliche ?nderungen verz?gerungsfrei aufgezeichnet werden konnten.相似文献
163.
Sarmistha Das Samirgopal Bhattacharya Rupendra Nath Banerjee Debabrata Banerjea 《Transition Metal Chemistry》1982,7(5):249-252
Summary The title complex aquates in acid media, first to [Co(mal)-(H2O)2(en)]+ (1) (Step 1) and subsequently to [Co(H2O)4(en)]3+
(2) (Step 2). Complex species (1) has been separated and characterised in solution. While Step 1 involves only a second-order acid catalysed path, Step 2 involves both a first-order acid independent path and a second-order acid catalysed path. The rate constants and activation parameters evaluated for these reaction paths have been compared with those for similar carboxylato-cobalt(III) complexes. This, together with an observed isokinetic relation, indicates that the rate-determining step involves opening of the unprotonated (in the spontaneous acid independent path) or the protonated (for the acid catalysed path) chelate ring of the malonate ligand and insignificant solvation of the central metal ion. 相似文献
164.
Masihhur R. Laskar Tapas Ganguli A. A. Rahman A. P. Shah M. R. Gokhale Arnab Bhattacharya 《固体物理学:研究快报》2010,4(7):163-165
We report the metal organic vapor phase epitaxy (MOVPE) growth and characterization of non‐polar (11 0) a ‐plane Alx Ga1–xN on (1 02) r ‐plane sapphire substrates over the entire composition range. Alx Ga1–xN samples with ~0.8 μm thick layers and with x = 0, 0.18, 0.38, 0.46, 0.66, and 1.0 have been grown on r ‐plane sapphire substrates. The layer quality can be improved by using a 3‐stage AlN nucleation layer and appropriate V/III ratio switching following nucleation. All a ‐plane AlGaN epilayers show an anisotropic in‐plane mosaicity, strongly influenced by Al incorporation and growth conditions. Careful lattice parameter measurements show anisotropic in‐plane strain that results in an orthorhombic distortion of the hexagonal unit cell, making Al composition determination from X‐ray diffraction difficult. In general lower Al incorporation is seen in a ‐plane epilayers compared to c ‐plane samples grown under the same conditions. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
165.
S. F. Timashev Yu. S. Polyakov R. M. Yulmetyev S. A. Demin O. Yu. Panischev S. Shimojo J. Bhattacharya 《Laser Physics》2010,20(3):604-617
In our earlier study dealing with the analysis of neuromagnetic responses (magnetoencephalograms—MEG) to flickering-color
stimuli for a group of control human subjects (9 volunteers) and a patient with photosensitive epilepsy (a 12-year old girl),
it was shown that Flicker-Noise Spectroscopy (FNS) was able to identify specific differences in the responses of each organism.
The high specificity of individual MEG responses manifested itself in the values of FNS parameters for both chaotic and resonant
components of the original signal. The present study applies the FNS cross-correlation function to the analysis of correlations
between the MEG responses simultaneously measured at spatially separated points of the human cortex processing the red-blue
flickering color stimulus. It is shown that the cross-correlations for control (healthy) subjects are characterized by frequency
and phase synchronization at different points of the cortex, with the dynamics of neuromagnetic responses being determined
by the low-frequency processes that correspond to normal physiological rhythms. But for the patient, the frequency and phase
synchronization breaks down, which is associated with the suppression of cortical regulatory functions when the flickering-color
stimulus is applied, and higher frequencies start playing the dominating role. This suggests that the disruption of correlations
in the MEG responses is the indicator of pathological changes leading to photosensitive epilepsy, which can be used for developing
a method of diagnosing the disease based on the analysis with the FNS cross-correlation function. 相似文献
166.
D. Sen J. S. Melo J. Bahadur S. Mazumder S. Bhattacharya G. Ghosh D. Dutta S. F. D’Souza 《The European physical journal. E, Soft matter》2010,31(4):393-402
Morphological transformation during evaporation-induced self-assembly of a mixed colloidal suspension in micrometric droplets
has been investigated. It has been demonstrated that a buckling-driven shape transition of drying droplets of mixed colloidal
suspension takes place during evaporation-induced self-assembly. Further, it is also shown that the distortion modulations
get significantly amplified with enhancement in volume fraction of anisotropic soft colloidal component of the mixed colloids.
It has been argued that the reduction in elastic modulus of formed shell, at the boundary of a drying droplet, and the anisotropic
nature of one of the colloidal components facilitate the deformation process. Hierarchical structures of these assembled colloidal
grains have been probed using electron microscopy and scattering techniques. 相似文献
167.
Mandira Sinha H. Majumdar P. Basu Subinit Roy R. Bhattacharya M. Biswas M. K. Pradhan R. Palit I. Mazumdar S. Kailas 《The European Physical Journal A - Hadrons and Nuclei》2010,44(3):403-410
Fusion excitation functions are measured for the system 6Li + 28Si using the characteristic $ \gamma$ -ray method, encompassing both the sub-barrier and above-barrier regions, viz, E lab = 7-24 MeV. Two separate experiments were performed, one for the above-barrier region ( E lab = 11-24 MeV) and another for the below-barrier region ( E lab = 7-10 MeV). The results were compared with our previously measured fusion cross-section for the 7Li + 28Si system. We observed the enhancement of the fusion cross-section at sub-barrier regions for both 6Li and 7Li , but the yield was substantially larger for 6Li . However, for well-above-barrier regions, a similar type of suppression was identified for both the systems. 相似文献
168.
Michael DG Adamson P Alexopoulos T Allison WW Alner GJ Anderson K Andreopoulos C Andrews M Andrews R Arms KE Armstrong R Arroyo C Auty DJ Avvakumov S Ayres DS Baller B Barish B Barker MA Barnes PD Barr G Barrett WL Beall E Becker BR Belias A Bergfeld T Bernstein RH Bhattacharya D Bishai M Blake A Bocean V Bock B Bock GJ Boehm J Boehnlein DJ Bogert D Border PM Bower C Boyd S Buckley-Geer E Bungau C Byon-Wagner A Cabrera A Chapman JD Chase TR Cherdack D Chernichenko SK Childress S Choudhary BC 《Physical review letters》2006,97(19):191801
This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.). 相似文献
169.
Bhattacharya S Chattopadhyay S Laskar S Banerjee M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(2):313-319
Electron donor-acceptor (EDA) complexes of tri-n-octylamine (TOA) with [60]- and [70]fullerenes and some other electron acceptors have been studied in chloroform medium by absorption spectrophotometric technique. Charge transfer (CT) absorption bands are observed in the visible region. Vertical ionization potential of TOA was determined utilizing CT transition energy. Oscillator strengths, transition dipole strengths and resonance energies for all the complexes have been calculated. [60]Fullerene/TOA and [70]fullerene/TOA complexes are found to decay slowly with time. Kinetics of these reactions have been studied and activation energies for such processes have been estimated. Ab initio calculations suggest that complexation of [70]fullerene with TOA is enthalpy favoured. 相似文献
170.
William H. Perman Pratip Bhattacharya Jochen Leupold Alexander P. Lin Kent C. Harris Valerie A. Norton Jan-Bernd Hövener Brian D. Ross 《Magnetic resonance imaging》2010